Lapping machine



March 21, 1939- G. E. HULBERT ET AL LAPPING MACHINE Original Filed May 23, 1936 2 Sheets-Sheet l ZSnventor GEORGE E. HuLaER'T HERBERT S. INDE'E '3 e a L) 3:. attom March 21, 1939.

G. E. HULBERT ET AL 2,151,473

LAPPING MACHINE Original Filed May 25. 1956 2 Sheets-Sheet 2 Ill-Imam l:- IIIIIA VIIII WIIIIIIIIIIIIIII I A 'I VIII! Will u F195 3 t GEORGE E. HULEERT HERBERT '5'. INJJG'E Q a (Ittorneg front of the machine.

Patented Mar. 21 1939 UNITED STATES PATENT OFFICEv boro, Mass., assignors to Norton Company, Worcester, .Mass a corporation of Massachusetts Original application May 23, 1936, Serial No. 81,372. Divided and this application May 18', 1938, Serial No. 208,629

4 Claims.

tion is to provide an improved cage for a lapping machine which may be readily loaded from a single operating station. A further object of the invention is to provide a cage construction in which the cage may be readily indexed to facilitate loading the same from a single station in Other objects will be in part obvious or in part pointed out'hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts, as will be-exemplified in the structure to be hereinafter described,

and the scope of the application of which will be indicated in the following claims.

In the accompanying drawings, in which is shown one of various possible embodiments of the mechanical features of thisinvention,

Figure 1 is a side-elevation'of a lapping machine, having parts broken away and shown in section more clearly to show the construction;

Figure 2 is a plan view, on an enlargedscale, of the work carrying cage, 'having'partsbroken away and shown in section more clearly to show the construction;

Figure 3 is a cross sectional View taken approximately on the line 33 of Figure 2;

Figure 4 is a fragmentary plan view, on an enlarged scale, of a modifiedformof locking device for the work carrying cage; and

Figure 5 is a fragmentary cross sectional view taken approximately onthe 1ine5--5 of Figure 4. M A lapping machine has beenillustrated in the drawings which comprises a base 10 having a vertically extending support H on which is mounted a supporting arm l2'for an' upper lapping wheel l3. The lapping wheel 13 is supported by a plate M which is fixed to the lower end of a slidably mounted rack bar 15. The upper lap l 3 may be raised and lowered by means of a spokedwheel it which is mounted" on one endof a rotatable shaft IT. The shaft "carwas fries a gear inot shOwn) which; meshes withthe teeth ontherack bar l5 and serves, when the spoked wheel I6 is rotated, to raise or lower the upper lap 13.

In order to hold the lapping wheel I3 in an u per or inoperative position, a ratchet wheel 20 is mounted onthe end of the shaft H and is arranged to be engaged. by a pawl 21 pivotally mounted on a stud 22 which'is supported on the arm I2.

A lower lapping wheel is supported by a flanged plate 3| which is keyed to a rotatable sleeve "'32 which is journaled in-bearings 33 and 34 in the base Hi. The sleeve may be rotated in the manner shown in the prior United States patent to 'Indge No.-1,610,527, to which reference may be had fora more detailed disclosure. A tight pu1ley35 and a loose: pulley 36 are mounted on the outer end of a drive shaft-36 which is rotatably supported in bearings 3'1 and 38 in the base I0. Theshaft 36 carries a worm -39 which meshes with a wormgear 40 keyed to the rotatable sleeve 32. When a driving belt (not shown) is shifted from the loose pul1ey'36 onto the tight pulley 35, the shaft 36 and Worm "39 are rotated, thereby transmitting a rotary motion to the sleeve 32, the plate 3| and the lower ,lap 30.

A cage structure 49 is mounted between the lapping wheel 13 and the lapping wheel -3ll and is provided with apertures which are shaped to receive workpieces to be lapped. As shown in Figure 2, the cage structure 49 is provided with a pluralityof circular work receiving apertures 5| which serve to locate'and hold a plurality of 'work pieces 52 within the cage structure 49 for a lapping operation. The apertures -5I may be square or of any other irregular shape which -may correspond in design with the shape of the work piece to be lapped.

In order to provide a desired lappingaction between the work pieces and the relatively r0- tated lapping elements, the cage structure 49 is provided with a mechanism for gyrating the work carrying cage, so as tocontinuously change the relation of the work and the relatively rotatable lapping wheels. For ,this purpose a head 55 is keyed to'the upper ,end .of a rotatable sleeve -56, the rotatable sleeve 56 being provided with bearings 51 and 58 which rotatably fit on a stationary vertically extending shaft .59 which is" keyed to a projection' fifl of the base. The sleeve 56 is mounted in bearings GI and 62 which are supported in the rotatable sleeve 32 so that the sleeves32-and 56 may rotate relative to each other and relative to the stationary central shaft 58.

A gear 65 is keyed to the lower end of sleeve 32 and meshes with a gear 66 which is keyed to a bushing 61 rotatably mounted on a fixed stud 68. A gear 69 is also keyed to the bushing 61 and meshes with a gear 18 which is keyed to the lower end of the inner sleeve 56 and serves to rotate the head 56 at a slightly different speed from the rotation of the lap 38.

A gear 18 is keyed to the upper end of the stationary shaft 59 and meshes with a plurality of spaced pinions II which are rotatably supported on studs I2. The studs 12 are mounted on the rotatable head 55. The pinions II are formed integral with rotatable heads 13 each of which carries a driving or crankpin I I. In the construction illustrated there are three pinions 'II which are symmetrically spaced about the central shaft 59 and each of which carries a crankpin 14 which are arranged to engage apertures I5 (Fig. 3) within the cage 58. When the drive shaft 36 is rotated to transmit a rotary motion to the lower lap 38, the rotation of the sleeve 32 transmits a rotary motion through the gear 65, the gear 66, the gear 69, the gear '18 and the sleeve 56 to rotate the head 55 which serves to revolve the studs I2 about the central stationary shaft 55. The geared connection between the stationary shaft and the heads I3, which includes the gear I8 keyed to the upper 'end of the shaft, serves to rotate the pinions 1| during the revolution of the studs I2 and cause a, rotation of the heads 13 to transmit a combined rotary and gyrating movement to the cage to carry the work pieces through an irregular path between the lapping wheels for a lapping operation. The construction thus far described is identical with that shown in the prior patent to Indge No. 1,610,527 dated December 14, 1926, to which reference may be had for a more detailed disclosure.

While the machine illustrated and above described shows an upper stationary lap which is moved vertically toward and from a lower rotatable lap, this invention is equally applicable to other types of lapping machines in which either or both of the lapping wheels are rotatable and movable toward and from each other.

In the operation of a lapping machine, especially a lapping machine in which the cage and the lapping wheels are of relatively large diameter, it is desirable to provide a means for readily loading the cage, that is removing the finish lapped work pieces therefrom after a lapping operation and inserting new pieces of work in the machine from a single operating station in front of the machine, thereby facilitating the loading of the machine. In the preferred construction the cage structure 49 is preferably formed in two parts, an outer work carrying cage 58 which is provided with work receiving apertures 5|, and an inner supporting member 18. The supporting member I8 comprises a pair of spaced plates 88 and 8| which are held in spaced relationship with each other by means of a plate 82. The plates 80, 8| and 82 are held in fixed relationship with each other by studs 83 which pass through holes in the plates. The three plates 88, 8| and 82 form an annular groove 84 which serves to rotatably support the work carrying cage 58.

It is desirable to provide a suitable driving connection between the work carrying cage 58 and the central supporting member I9 so that during a lapping operation, the work carrying cage 58 and its inner supporting member I9 may be rotated and gyrated simultaneously by the mechanism above described. The work carrying cage 58 is provided with an inner internal aperture 85 which is a clearance hole therethrough so as to permit free rotation of the work carrying cage 58 relative to the supporting member I9.

In the preferred construction, a pawl and ratchet mechanism is interposed between the work carrying cage 58 and its central supporting plates 88, 8| and 82. The work carrying cage 58 is provided with a plurality of notches 8'1 which are arranged to be engaged by a plurality of spaced pawls 88 which are pivotally mounted on studs 89. A spring 98 is carried by the inner plate 82 and is arranged to exert a pressure tending to turn the ratchet pawls 88 in a clockwise direction to hold the pawls 88 in engagement with the notches 81 so that when the supporting member 19 is rotated in the direction of the arrow, as shown in Figure 2, the pawls 88 carried by the central supporting member I9 will drive the work carrying cage 58 so that they rotate and gyrate simultaneously.

The central supporting member I9 is provided with three spaced bushings I88 each of which is provided with a pin receiving aperture I5 which are adapted to engage the driving pins 14. The bushings I88 pass through the three plates 88, 8| and 82 and are held in adjusted position therein by means of nuts IIlI. Each of the bushings I80 is provided with an adjusting screw I82 which is adapted to bear against the upper end of the crankpin l4 and serves to adjust the position of the supporting member '19 and work carrying cage 58 relative to the lower lap so that the work carrying cage 58 may be adjusted close to or spaced from the operative surface of the lap 38, depending upon the thickness of the work pieces which are to be lapped. The adjusting screws I82 are held in adjusted position by lock nuts I83 so that after the screws have been adjusted to position the work carrying cage 58, as desired, the locking nuts I83 may be tightened to lock the cage in its adjusted position.

After the lapping operation has continued on a plurality of work pieces 52 so that they have been lapped to the desired extent, the rotation of the lapping wheels I3 and 38 is then stopped by shifting the driving belt (not shown) from the tight to the loose pulley, and the wheels are thereafter separated from each other. The work piece adjacent to the loading station is then removed from the machine and a new piece of Work 52 is inserted thereinstead, and the work carrying cage member 58 may then be rotated relative to the supporting member 19 by manually rotating the work carrying cage 58 against the ratchet pawls 88 in a counterclockwise direction (Fig. 2) so that the next cage aperture may be loaded from the same position in front of the machine. After the second station has been loaded, the work carrying cage 58 may be further rotated, and so on until all of the finish lapped pieces have been removed and new pieces to be lapped inserted thereinstead for another lapping operation.

A modified form of locking device has been illustrated in the modification shown in Figures 4 and 5. As indicated in the modification, the work carrying cage 58 is provided with a notch or recess I28 which is arranged to be engaged by a slidable plunger |2| which slides within a radially extending slot I22 in the plate 82. The

plunger or locking pin I 2| is connected by a pivot pin I23 with a strap I24 which surrounds a rotatable eccentric plate I25. The eccentric plate I25 is rotatably supported. between the plates 80 and 81. A projecting hub I26 serves as a trunnion to support the upper end of the cocentric plate, and a stud 21 passing through an aperture in the lower plate SI serves as a trunnion to rotatably support the eccentric I25. When it is desired to lock the supporting member it and the work carrying cage 55 together for a lapping operation, a manually operable handle I35 is moved into the full line position, as shown in Figure 4, so that the eccentric plate I25 moves the plunger I2I downwardly into engagement with the notch I20 so as to lock the work carrying cage 55 to the plates 80, BI and 82 so that they may be rotated and gyrated simultaneously. When the Work pieces have been lapped to a predetermined extent, and the laps have been separated to an inoperative position, the handle I30 is moved into the dotted line position I 30a (Fig. 4) which serves to rotate the eccentric I25 into the dotted line position I25a. and thereby to withdraw the plunger I2l from the notch I26 so that the work carrying cage 55 may be rotated relative to the supporting member 19 for unloading and loading of work pieces.

The operation of this lapping machine is readily apparent from the foregoing disclosure. Assuming the lapping wheels I3 and 3!] to be separated in an inoperative position, the work carrying cage 5|] is rotated manually relative to the supporting member 19 from an operating station in front of the machine and a work piece 52 is inserted in each of the apertures 5!, after which the driving belt is shifted from the loose to the tight pulley to start a relative rotation between the lapping wheels and at the same time to start the rotation and gyration of the supporting member 19 and the work carrying cage 50 to simultaneously lap a plurality of work pieces to a predetermined extent. After the work pieces have been lapped to the required extent, the laps are again relatively separated from the work pieces and the lapped work pieces are removed therefrom and new pieces inserted therein as the work carrying cage 50 is rotated relative to the supporting member 19, thereby facilitating loading of the machine and enabling a machine of large diameter to be loaded from a single operating station in front of the machine.

It will thus be seen that there has been provided by this invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

We claim:

1. A lapping machine comprising a pair of opposed lapping wheels, means to relatively rotate said wheels, means to move said wheels relatively toward and from each other, a cage supporting member, means to move said cage supporting member through an irregular path relative to said lapping wheels, a work carrying cage rotatably supported on said member, and a manually operable slidable driving plunger releasably to lock said cage to said supporting member so as synchronously to move said cage with said memher when the member is moved in an irregular path for a lapping operation.

2. A lapping machine comprising a pair of opposed relatively rotatable lapping wheels, means to relatively rotate said wheels, means to cause a relative approaching or receding movement therebetween, a cage supporting member, means to move said support through an irregular path relative to said relatively rotatable lapping Wheels, a work carrying cage having a plurality of work receiving apertures which is rotatably mounted on said support, locking means including a slidably mounted plunger interposed between said support and cage releasably to lock the cage to the support so that the cage is synchronously moved through an irregular path with the support for simultaneously lapping a plurality of work pieces, and manually operable means including a cam to actuate said locking plunger to permit rotation of said cage to facilitate loading of the same.

3. A work support for a lapping machine comprising a central supporting member which is arranged for an irregular movement, a work carrying cage having a plurality of Work receiving apertures which is rotatably supported thereon, means to move said member in an irregular path, and means including a manually operable cam actuated plunger to lock said cage to said member during a lapping operation so as to move said cage in synchronism with said member when the supporting member is moved through an irregular path.

4. A work support for a lapping machine comprising a central supporting member which is arranged for a gyrating movement, a work carrying cage rotatably supported thereon and having a plurality of work receiving apertures therein, means including a releasable slidable plunger to lock said work carrying cage to said supporting member so that the cage moves in synchronism with said supporting member, and means including a manually operable lever operatively connected to actuate said locking plunger so as to permit a rotation of the cage to facilitate loading of the same when the supporting member is stationary.

GEORGE E. HULBERT. HERBERT S. INDGE. 

